"Meet Winnie a single mother of 5 who's dedicated her life to her young children," said Williams on Twitter. "This is what inspires me!"
Over the years, Williams has made many heartfelt gestures for causes he believes in.
During the Rugby World Cup, he offered two tickets to the Rugby World Cup semifinal to a Syrian refugee and a friend.
He also made headlines around the world when he gave away his Rugby World Cup winners medal to a young pitch invader who was tackled by a security guard.
However one of his most generous acts was for a cause closer to home, during his stint in professional boxing when he gave $100,000 of his fight fee to the Christchurch Earthquake Appeal after he beat Alipate Liava'a in Auckland.